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In Vivo

Research Briefs

The structure of resistin, a protein produced by fat cells, may reveal how obesity and diabetes are connected.

The structure of resistin, a protein produced by fat cells, may reveal how obesity and diabetes are connected. The structure, part of PSI's first phase, was published last year by Lawrence Shapiro.

Unravelling the Mystery Of Essential Tremor

In a recent population-based survey of more than 5,000 elderly individuals in three communities in Spain, investigators found that the incidence of essential tremor (ET) was approximately 10 times higher than previously believed. In that study, published in the May 2005 issue of Neurology, Elan D. Louis M.D., M.S., associate professor of neurology and associate chairman of neurology at P&S, along with colleagues in Spain, used a more sensitive method of detecting ET cases, thereby resulting in the higher number of cases.

Although it is one of the most common neurological diseases, ET has remained somewhat of a mystery. A major stumbling block has been the lack of brains for postmortem study. Dr. Louis and his colleagues recently established the Essential Tremor Centralized Brain Repository at Columbia to study the biological basis for ET. In a study published in the June 2005 Archives of Neurology, Dr. Louis and collaborators examined the first brain that they received and found it contained numerous Lewy bodies – microscopic, circular inclusions in neurons that are the hallmark of Parkinson's disease. This research suggests that the links between ET and Parkinson's disease, both of which are characterized by tremor, are even closer than previously recognized. The research also expands the clinical spectrum of Lewy body disease to include not only patients with Parkinson's (estimated to affect 0.5 to 1 million Americans) but also some as yet unknown number of patients with ET (estimated to affect more than 10 million Americans).

Dr. Louis and his colleagues continue to study ET brains through the brain bank; 10 such brains are now under study and it is hoped that they will shed additional light on this common neurological disorder.

The Neurological Disorders in Central Spain study is funded by the Spanish Health Research Agency and the Spanish Office of Science and Technology. The Columbia brain bank is funded by the NIH and the International Essential Tremor Foundation.

Dentists Urged to Look Beyond Teeth

Smoking and diabetes are two conditions that degrade oral and overall health, yet most dentists do little to help smokers quit or proactively manage their diabetic patients, nor do they feel it's their responsibility to be actively involved, according to a survey conducted by SDOS researchers and published in the August 2005 Journal of the American Dental Association (JADA).

In an accompanying editorial, JADA editor Michael Glick, D.M.D., wrote that such primary care activities should no longer be a choice. "The impact of oral health on overall well being is undeniable, and the impact of the oral health care provider on overall health no longer is conditional."

The survey of 105 general practice dentists found that while 75 percent ask patients about smoking, less than 10 percent frequently provide follow-up or referral for smokers. That half of general dentists view smoking cessation as peripheral to dentistry is a barrier to their becoming more actively involved. A similar pattern was observed for diabetes.

"Our data show that it's not enough to give dentists more information about smoking cessation and actively managing diabetic patients," says the study's lead author, Carol Kunzel, Ph.D., associate professor of clinical dentistry. "We also need to overcome dentists' attitudes toward becoming more active primary care providers."

This study was supported by a National Institute of Dental and Craniofacial Research grant awarded to Ira Lamster, D.D.S., professor of dentistry and dean of SDOS.

New Role for Form Of Estrogen Found

A team led by C. Dominique Toran-Allerand, M.D., Sc.D., professor in the Departments of Anatomy & Cell Biology, and Neurology, has shown, for the first time, that high endogenous levels of 17alpha-estradiol are present in the postnatal and adult male and female brain. The findings suggest that since 17alpha-estradiol is not present in the circulation and is unaffected by ovariectomy, castration and /or adrenalectomy, it is likely to be made in the brain. Moreover, since 17alpha-estradiol elicits activation of major intracellular signaling pathways, its presence in the brain makes it uniquely positioned to activate the entire subsequent range of differentiative and neuroprotective signaling pathways. The significance of this finding is heightened by the fact that 17alpha-estradiol is the selective hormone for "ER-X," the estrogen receptor that Dr. Toran-Allerand and her team recently discovered. Dr. Toran-Allerand's findings challenge the view that 17alpha-estradiol is without biological significance, as is generally believed. Far from being a biologically inactive estrogen, 17alpha-estradiol may have very important neural functions throughout life, with enormous implications for hormone replacement strategies at menopause and in the treatment of various neurodegenerative disorders, including Alzheimer's disease and ischemic stroke.

The paper was published in the online version of Endrocrinology, which can be accessed at http://endo.endojournals.org/cgi/content/abstract/en.2004-1616v1.

This research was funded by the NIMH and the Office of Research in Women's Health.

Health Savings Accounts For Uninsured Get Thumbs Down

Health Savings Accounts (HSAs) are unlikely to be an important contributor to expanding coverage among uninsured individuals, according to an analysis by researchers in the Mailman School's Department of Health Policy and Management.

HSAs permit enrollees to save money, tax-free, that they can use to cover out-of-pocket expenses associated with health care. When used in combination with a high-deductible plan, proponents argue that HSAs offer a new and valuable health insurance option that will expand the number of Americans with coverage.

But an economic analysis by Sherry Glied, Ph.D., professor and chairman of the department, and Dahlia Remler, Ph.D., assistant professor, found HSAs are likely to increase the number of newly insured adults by fewer than 100,000, about 0.3 percent of the adult uninsured population. Most of the uninsured do not face high-enough tax rates to benefit substantially from HSA contributions deductibles.

In addition, the authors warn that current HSA provisions – particularly if they are combined with proposed premium deductibility – could encourage well-compensated healthy workers to abandon job-based coverage, a move that could undermine the entire structure of job-based coverage at small firms.

The results of their research, sponsored by the Commonwealth Fund, are published in The Effect of Health Savings Accounts on Health Insurance Coverage, the Common-wealth Fund, April 2005.

Source of Suppressor Immune Cells Found

Yoga in 105º F heat may be the trendiest way to achieve harmony within the body, but for immunologists looking for internal harmony, T regulatory cells (Tregs) are the hottest things around.

Written off as illusions in the '80s, Tregs are now believed to be central to the body's ability to prevent immune attacks on itself. As such, manipulating Tregs has huge potential in treating autoimmune disorders, preventing organ rejection and improving the power of cancer vaccines.

Those therapies may be a little closer to reality with the discovery of a pure source of human Tregs in circulating blood, which until now were elusive. The cells were identified by Danila Valmori, Ph.D., associate professor of medicine, and Maha Ayyoub, Ph.D., assistant professor of medicine and surgery, who are also immunologists at the Ludwig Institute for Cancer Research.

"Their most obvious application right now is in organ transplantation," Dr. Valmori says. Giving Treg precursors to a transplant recipient may prevent the patient's immune system from attacking the donated organ.

The research was supported by the Ludwig Institute for Cancer Research and the Cancer Research Institute and published in the Aug. 1 Journal of Clinical Investigation.

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